Variable Intensity Laser Treatments of the Skin

ABSTRACT

A method for providing localized heating of the dermal layers of skin of a patient, using energy in the form of a group of pulses having defined parameters in a controlled manner. This method preferably uses an optical delivery system to deliver pulsed energy to a specific spot of skin so that targeted layers of the affected skin are heated to a desired temperature range. The temperature range is optimally selected to maximize treatment efficacy while minimizing pain to the patient. Example applications include reducing wrinkles, acne, hair, scar tissue, warts, and promoting wound healing. In this method, the temperature of the selected locus rises quickly to the desired temperature range, then is maintained within a controlled range with a relatively flat temperature profile. The method maintains the temperature by controlling one or more of a pulse energy intensity, pulse width, and pulse frequency or time delay between pulses.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/065,640, filed on Oct. 29, 2013, and claims the benefit under 35 USC119(e) of U.S. Provisional Application No. 61/721,331, filed on Nov. 1,2012, both of which are incorporated herein by reference in theirentirety.

BACKGROUND OF THE INVENTION

Lasers for treating skin ailments, hair removal, and other dermalprocedures were first introduced in the 1990s. Laser wavelengths areabsorbed in the skin or in other tissues to provide limited localizeddamage, which causes the body to respond in a desired manner. Oneexample includes lasers that provide localized damage to hair folliclecells, which causes permanent hair removal. Another example includeslasers that provide localized damage to the dermal layers, which causeswrinkle or acne reduction in the skin.

A schematic drawing of the outer layers of the skin is shown in FIG. 5.The outer layer of the skin, the epidermis, is the familiar outer layerof skin cells. Below the epidermis is the dermis, which comprises livingepidermal. cells, local vascularization, and additional structuresincluding hair follicles, collagen, elastin and secretory cells. Thedermis is the primary target site for treatment of the skin for lastingor permanent changes. It is most desirable to leave the epidermisunaffected and undamaged during a treatment procedure. To achieve this,the epidermis can be intentionally cooled during such treatmentprocedure, or the procedure can be tailored to avoid any significantheat to the epidermis. This approach will minimize pain and recoverytimes and ideally with no visible scarring, redness, or side effects.

There are a number of past and current examples of laser treatments forskin. For example, U.S. Pat. No. 8,029,553 to Nemenov describes a lasersystem and process using a near-IR laser at 980 nanometers (nm) toproduce controlled variable heating and stimulation of single nervefibers in tissue, while avoiding nerve damage. U.S. Pat. No. 7,856,985to Mirkov et al. and U.S. Published Patent Application No. 2011/0152847by Mirkov et al. describe remodeling of skin using high intensity laserpulses to shrink skin collagen, and using low intensity radiation tostimulate fibroblasts for renewed collagen production. U.S. Pat. No.7,413,572 to Eimerl et al. describes irradiating tissue with a sequenceof optical pulses. Then, tissue properties are measured and used to varythe intensity of irradiation to produce desired results, U.S. Pat. No.6,998,567 to Yeik describes the creation and delivery of laser pulsetrains.

U.S. Pat. No. 6,595,985 to Tobinick uses laser pulses to remove hairfollicles and cooling the epidermis with fluid spray to prevent skindamage. U.S. Pat. Nos. 6,165,171 and 6,168,589 to Tobinick describe twolasers of different wavelengths to remove hair follicles. U.S. Pat. No.5,836,999 to Eckhouse et al. discloses treatment of psoriasis withnon-laser optical energy. In this example, pulse number and width areselected to control penetration, and cooling may be supplied to the skinsurface. U.S. Pat. No. 5,689,520 to Hoang describes a method andapparatus for obtaining a variable output waveform in surgery.

U.S. Pat. No. 5,269,778 to Rink et al. and U.S. Pat. No. 4,950,268 toRink use pulses for vaporization of tissue at a tissue site producinglocalized plasma.

SUMMARY OF THE INVENTION

The attributes of optical power, pulse width (also referred to as pulseduration), time delay between pulses, and total number of pulses dictatethe total time and total energy during a treatment cycle. The sametreatment cycle can be represented identically with the terms opticalpower, pulse frequency, duty cycle, and total treatment time. Forexample, the same pulse treatment can be expressed by either using pulsewidth and time delay between cycles or duty cycle and pulse frequency.Thus, these combinations of terms may be interchangeable as it relatesto the following explanations of methods of treatment. Optical power(also expressed as energy intensity, or laser power if a laser is usedto generate the optical energy) is typically varied by setting thecurrent that flows through the light emitting element such as a laserdiode or light-emitting diodes (LED).

Typically, for a given treatment, the system user will fix the fourattributes listed above (laser power, pulse width, time delay betweenpulses, and total number of pulses) through the system controlsinterface. Once these settings are fixed, the laser will be turned onand the patient will be treated with the sequence of pulses asdetermined by these settings. Such an approach delivers a consistentstream of energy into the patient as illustrated in FIG. 7. Thisgenerates a thermal profile in the skin which rises linearly thendecreases linearly once the laser power is removed. However, this linearpower implementation and linear temperature profile is not ideal fortreating skin ailments.

The number of pulses or the total time the laser is in operation istypically fixed for a given treatment setting. Typically, all pulses areidentical in pulse width and in time delay between pulses. The number ofpulses is controlled by a computer or electrical system to repeat thepulsing sequence until the defined number of pulses is reached. Thelasers are pulsed to allow for the human tissue to absorb the energywithout an extreme energy spike within the tissue which can causeburning or similar unwanted outcomes. The time delays between pulsesallow the tissue to relax and the energy to be absorbed and spreadwithin the tissue before the next pulse introduces additional energyinto the tissue.

A more ideal treatment for skin disease, skin ailments, skin wrinkles,and the like is to raise the temperature of the exact depth and area ofthe skin where a thermal response is desired to a relatively exactingtemperature that is known to promote a desirable cellular response,Then, the temperature is maintained until the promoted response hassufficiently taken place. To achieve the desired temperature profile,the laser system must operate in a non-linear fashion. For example, thelaser may initially drive at a high fluence (high rate of energytransfer) into the skin until the desired temperature is reached, lowerits fluence to allow the energy to evenly distribute in the targetedskin, and then finally modify its fluence to maintain this desireddermal temperature.

Current laser treatment for skin wrinkles uses a set of repetitive laserpulses, as illustrated in FIG. 7, to raise the temperature of the skinto temperatures of greater than 60 degrees Celsius (C) in smallfractional areas of the skin, which typically represents less than 10percent of the entire skin area. The skin cells affected by this laserenergy are damaged or destroyed, and in response, send out heat shockprotein signals and signals causing the body to fully regenerate thesedestroyed skin cells. This method relies on cells adjacent to thedamaged cells for help to rebuild the skin quickly. This treatment istypically repeated many times using daily or weekly treatment frequency.This not only randomizes the locations of the skin damaged by thetreatment, but also provides the ability to treat all skin over time.Over time, most or all of the skin is regenerated. This method hasseveral drawbacks such as causing pain to the patient, redness of theskin, and high laser system costs.

An alternate method for skin wrinkle reduction was published in 2010 inthe Reference Heat-Shock Protein Study, titled “The effect of heatshocks in skin rejuvenation,” by Susanne Dams. In this study, analternate method is evaluated that raises the skin temperature to only45 degrees C. According to Dams, the lower temperature stimulatesheat-shock protein formation while also maintaining an energy level andtemperature within the skin that is typically below the pain thresholdfor most patients. Studies have shown that the temperature of the skindermis is the salient factor in promoting the desired medical effect ofinterest. As a result, it is desirable to reach the needed temperaturequickly and then maintain that specific temperature for a period oftime. The time at which the skin is maintained at that given temperatureoften correlates with the effectiveness of treatment.

In the case of wrinkle reduction within skin, it is desirable to raisethe temperature of the dermal layer of the skin above 39 degrees C.Doing so triggers the dermal cells to release heat-shock proteins (HSI')to promote collagen formation, new cell formation, and collagenreconfiguration, which may reduce skin wrinkles. At a temperature of 45degrees C., humans begin to feel pain in the dermis. Thus, an ideal wayto stimulate HSP and other cell benefits without incurring pain is toraise the dermal temperature between 39 degrees C. and 45 degrees C.while also maintaining this temperature for a fixed period of time.Though the period of time depends on the specific treatment, it isideally greater than 0.5 seconds.

At these temperatures, the dermal cells release heat-shock proteins,which promote collagen remodeling, new collagen growth and/or elastinformation. Collagen remodeling is a relaxing of the collagen, whichallows tangled and twisted collagen to reform into flat linear collagenstrands. This promotes soft, smooth, and healthy looking skin. Theflattening of the existing collagen is combined with the addition of newcollagen, as promoted by the introduction of the heat-shock protein, toreduce or eliminate fine wrinkles in human skin. The aforementioned Damsstudy noted that increasing temperature higher than 45 degrees C. in theskin's dermal layer did not have a significant additional benefit. Thus,raising temperature in the dermis to between 39 degrees C. and 45degrees C. is highly preferential, as it maximizes effectiveness withminimal energy (high efficiency), while also minimizing pain and otherskin side effects such as redness.

The ideal laser treatment approach involves raising the dermaltemperature to between 39 degrees C. and 45 degrees C. and maintainingthis temperature for a time such that when the laser is removed, thetemperature continues to remain at the elevated temperature for muchlonger than the time of the treatment itself :Ideally, the lasertreatment time is between 0.2 and 1.5 seconds and causes a temperatureelevation within the range of 39 degrees C. to 45 degrees C. in the skinthat lasts for 1 second or longer.

An improved method of laser treatment is needed to more precisely applyenergy into the skin. The preciseness of the energy application of theimproved method will allow the skin to reach a relatively fixedtemperature level while avoiding temperature spikes, and will prolongthe treatment time at the desired temperature to maximize efficacy ofthe dermal treatment.

A new method of laser treatment has been developed to raise thetemperature in desired portions of a tissue to a desired temperaturelevel and to maintain this temperature for a desired amount of time.This method provides the following advantages: 1) increased efficacy, 2)increased safety, with burning of the skin eliminated, 3) increasedspeed of treatment, 4) more localized heating of the skin to avoidcollateral damage to areas not of interest, 5) increased usefulness fortreatment of all skin types and colors, 6) increased comfort and painavoidance in the treatment process.

This invention relates to an improved method employing a laser apparatusfor generating heat in the dermal layers of the skin. Specifically, theinvention relates to sending out a series of laser pulses to a targetedarea of skin. The pulses are pre-defined to vary in pulse intensity,pulse width, and delay between pulses. This enables the temperature inthe dermal layer to rise quickly to a desired temperature range, thenlevel off and stay within the temperature range without becomingsignificantly hotter or colder. This provides an improved cellularresponse without overheating portions of the skin, which avoidscollateral damage and pain to the patient's skin.

In general, according to one aspect, the invention features a method forproviding localized heating of target spots of skin of a patient. Thismethod includes applying laser energy to the target spots in an affectedarea of skin such that the skin is heated so that a temperature of eachtarget spot rises quickly to a desired heating temperature range. Also,this method includes maintaining the temperature in the target spotswithin the desired heating temperature range by controlling, in pulsesor continuously, at least one beam parameter including an energyintensity, a pulse width, or a time delay between pulses. One or more ofthe beam parameters change throughout the application of the laserenergy.

The energy is preferably delivered to the target spot based on pulsedbeam parameters. The pulsed beam parameters are selected from the pulsewidth, the time delay between pulses, and the pulse energy intensity (orequivalently duty cycle and pulse energy intensity). Then, one or morepulsed beam parameters are initially set to raise the temperature in theskin, then as the heating progresses the parameters are changed so as tomaintain the desired temperature range in the skin.

In one example the energy is delivered to the target spot as acontinuous energy beam, where time delay between pulses is zero (thereare no separate pules) and only the energy intensity varies with timeduring the heating.

In one example, the pulses are applied in a first group of pulses toquickly heat the skin to a target temperature, and thereafter the pulsesare applied in a second group of pulses to decrease a rate oftemperature increase in the target, followed by a third group of pulsesto maintain the temperature of the target for a defined period. Inanother example, the second group of pulses provides less energy/timethan the first group of pulses and greater than the third group ofpulses. Preferably, a group of pulses after the initial group of pulsesprovides less energy/time than the first group of pulses and less than asubsequent group of pulses.

According to another example, an interval between pulses increases overtime to maintain a tissue temperature in the desired heating temperaturerange during treatment. The pulses are of variable width and the widthof the pulses decreases over time to maintain a tissue temperature inthe desired heating temperature range during treatment.

Preferably, the energy intensity varies over time to maintain a tissuetemperature in the desired heating temperature range during treatment.The treatment can be utilized to reduce any or all of the following:skin wrinkles, acne, hair, skin discoloration such as age spots,bacterial infections, viral infections, fungal infections, scar tissueor appearance thereof, cellulite, warts, or wound infection.

In general, according to another aspect, the maintained temperature ofthe method is greater than about 39 degrees Celsius. Preferably, themaintained temperature is greater than about 39 degrees Celsius and lessthan about 45 degrees Celsius. The energy is typically provided by alaser source, ultrasound or a radio-frequency (RF) source, Preferably,the energy conveyed maintains a dermal temperature of the target spotsbetween about 39 degrees Celsius and about 45 degrees Celsius forgreater than about 0.5 seconds.

In one implementation, a safety sensor near an aperture detects acontact or near-contact with the skin, and the method includes onlyemitting energy while the safety sensor continues to detect contact ornear-contact with the skin.

In another example, a laser device that forms the method is connected bya wire or through wireless communications to another device such as acomputer to complete one or more operations to the laser device, theoperations including updating device software, downloading device data,and charging device battery. Preferably, once the laser device isconnected to another device, the laser device automatically launches aprogram to begin data communications between the devices.

Preferably, the laser device uses an optical wavelength between 1380 nmand 1570 nm. The laser device can be utilized for promoting the healingof wounds, and for promoting vaccine transportation throughout thepatient.

In general according to another aspect, the invention features ahandheld laser system for providing localized heating of target spots ofskin for treating a patient. The system comprises a laser engine forgenerating light that is applied to the target spots of skin and acontroller that drives the laser engine to generate light to maintainthe temperature in the target spots within the desired heatingtemperature range by controlling, in pulses or continuously, at leastone beam parameter of the laser engine including an energy intensity,pulse width, or a time delay between pulses, such hat one or more of thebeam parameters change throughout the application of the energy.

The above and other features of the invention including various noveldetails of construction and combinations of parts, and other advantages,will now be more particularly described with reference to theaccompanying drawings and pointed out in the claims. It will beunderstood that the particular method and device embodying the inventionare shown by way of illustration and not as a limitation of theinvention. The principles and features of this invention may be employedin various and numerous embodiments without departing from the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, reference characters refer to the sameparts throughout the different views. The drawings are not necessarilyto scale; emphasis has instead been placed upon illustrating theprinciples of the invention. Of the drawings:

FIG. 1 is a perspective view of a handheld laser system;

FIG. 2 is an exploded view of the handheld laser system from FIG. 1;

FIG. 3 is a perspective view showing how the handheld laser system isheld prior to pressing a laser against skin for treatment;

FIG. 4 is a schematic cross-sectional view of the handheld laser systemduring treatment as it is engaged directly onto the skin;

FIG. 5 is a perspective view of the structures of the skin;

FIG. 6 is a flowchart illustrating the handheld laser system operation;

FIG. 7 is a graphical view of a simple pulse pattern in which all pulsesare the same in pulse intensity, pulse duration and time between pulses,providing a temperature profile that peaks and then declines;

FIG. 8 is a graphical view showing a dermal temperature profile as beingmaintained in a narrow window of dermal temperature by reductions inapplied laser power;

FIG. 9 is a graphical view defining additional features of FIG. 8;

FIG. 10 is a graphical view showing a pulse pattern in which pulses areconstant in pulse intensity, pulse width and change in intervals betweenpulses, providing a fixed temperature profile in the dermis;

FIG. 11 is a graphical view showing a pulse pattern in which pulseschange in pulse width with the same interval between pulses, pulseintensity, providing a fixed temperature profile in the dermis;

FIG. 12 is a graphical view showing a pulse pattern in which pulseschange in pulse width and change in intervals between pulses with fixedpulse intensity, giving a fixed temperature profile in the dermis;

FIG. 13 is a graphical view showing a change in pulse width, pulse eight(intensity), and time interval between pulses;

FIG. 14 is a graphical view showing a pattern of constant pulse widths,a low pulse height segment after a desired temperature is close to beingachieved, followed by a higher pulse height to maintain temperature inthe skin;

FIG. 15 is a graphical view showing the use of continuous laser energywith an initially high intensity decreasing to a lower intensity levelwhen the desired temperature has been attained in the tissue;

FIG. 16 is a graph of laser current versus time for the laser system ata low setting, utilizing high power pulses followed by medium powerpulses followed by low power pulses;

FIG. 17 is a graph of laser current versus time for the laser system ata medium setting, utilizing high power pulses followed by medium powerpulses followed by low power pulses;

FIG. 18 is a graph of laser current versus time for the laser system ata high setting, utilizing high power pulses followed by medium powerpulses followed by low power pulses; and

FIG. 19 is a graph of laser current versus time for the laser system atan alternate high setting, utilizing high power pulses followed by lowpower pulses followed by medium power pulses.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a simplified handheld laser system 10 that performs the methodfor providing localized heating of target spots of skin for treating apatient. The system 10 is utilized for treating skin tissue and selecteddermatological conditions. Such conditions include acne, skin wrinkles,hair removal, skin discoloration such as age spots, and bacterial,viral, and, fungal infections. In addition, the system 10 reduces scartissue or its appearance thereof, reduces cellulite and warts, promoteswound healing and disinfection, and promotes the transportation ofvaccines throughout the body of the patient.

The system 10 includes an aperture 1 where light is emitted from thedevice 10, initiation button 2 to initiate the laser treatment sequence,and indicator lighting 3 to notify operator of system status andoperating program. The system 10 also includes power button 4 forselecting the power level and/or program sequence, port 5 to connect thedevice 10 to power the unit and/or to charge the battery and/orcommunicate with other devices, and handle 6 to encase the system 10 andprovide an ergonomic way to handle the system 10 in a human hand.

Port Scan also be used to connect the device 10 to another device suchas a computer. A computer communicates with the system 10 to update theprogram(s) or download data to the system 10, or communicate with thesystem over the internet, in examples. The laser system 10 in FIG. 1 iscompact and useful for such applications as portable laser operations athome, while traveling away from home, in a doctor's office, or placeswhere medical professionals can operate.

FIG. 2 shows additional details of the laser system 10 in a disassembled(exploded) manner. It shows how the laser system 10 includes a lightemitting device or laser engine 7 which has lens(es) and/or fiber opticsand a heat dissipation element. In one example, device 7 is constructedas described in U.S. Pat. Appl. Pub. No. US 2011/0122905A1, Pub. DateMay 26, 2011, by D. Bean and J. Callahan, which is incorporated hereinby this reference in its entirety. This laser system 10 also includes asafety sensor 8 which can determine if the light aperture 1 is inrelatively full contact with the skin.

The laser system 10 also includes an internal control board 9 which caninclude a controller such as a microprocessor(s), capacitors, batterycharge circuits, memory, and data communication chips, all of whichcontrols and powers the light emitting device 7 and receives inputs fromthe initiation button 2, power button 4, and port 5. In this example,the light emitting device 7 includes a fan for convection cooling of thelight emitting device. The fan blows air toward the skin through anaperture 1 or pulls air in the other direction away from aperture 1. Airtraveling through the aperture 1 driven by the fan is necessary to coolthe light emitting device in 7 and may act to cool or heat the surfaceof the skin directly outside of aperture 1 as a secondary function.

In general, the controller of the of the control board 9 drives thelaser engine 7 to generate light to maintain the temperature in thetarget spots within the desired heating temperature range bycontrolling, in pulses or continuously, at least one beam parameter ofthe laser engine 7 including an energy intensity, pulse width, or a timedelay between pulses, such that one or more of the beam parameterschange throughout the application of the energy.

FIG. 3 shows how the handheld laser system 10 can be oriented in auser's hand. This configuration allows for a comfortable and ergonomicgrip of the handle with the thumb naturally resting on the initiationbutton 2.

FIG. 4 shows a basic schematic of the handheld laser system 10 as it ispressed against the outer skin (epidermis) 27 of a patient. The contactconfiguration in FIG. 4 is used to press the device 23 against the skin28 such that the contact safety sensor 8 senses that the device 23 is ingood contact or close proximity with the epidermis 27 part of the skin28 one example, the safety sensor 8 is be made up of multiple sensorseach determining if skin is in contact around the circumference of theaperture 1. It is preferable to have multiple sensor reading headswithin the safety sensor 8, such that each sensor head is about 120degrees from each other around the perimeter of the aperture 1.

Also, the controller of the control board 9 preferably ensures that allof the sensor reading heads are touching the skin 28 to ensure there areno significant gaps in contact where emitting light could leak out fromthe desired treatment area. Reference 20 represents the light beingemitted into the skin 28 from the laser system 10 and penetratingthrough the epidermis 27 into the dermis 28 or skin layer. By choosingthe appropriate wavelength of the light emitter 7 within the system 10,the light will be absorbed at depths within the dermal layers accordingto the absorption characteristics of the wavelength. Wavelengths between1380 nm and 1570 nm are well suited to be absorbed in the dermis andreduce or eliminate acne, skin wrinkles, and many bacterial/viralinfections in the skin. Such penetration of laser energy between 100microns and 800 microns is desirable for these applications.

FIG. 5 shows the skin structure of a patient that includes the epidermis27, collagen layers 29, sebaceous gland 30, and dermis 28. The treatmentprovided by the system 10 enacts beneficial, long-lasting or permanentchanges to the dermis 28 without damaging or affecting the epidermis 27.

FIG. 6 is a flow chart outlining an example of how to use the lasersystem 10 for administering laser treatments using the handheld laserdevice 23 (system 10). In more detail, the power button 4 is pressed toenergize the system 10 in step 100. Once the power button 4 is engagedin step 100, the system 10 is programmed to launch into step 101 andprovide an audio signal, such as a jingle from a speaker or buzzerelement on the control board 9. Then, the indicator lighting 3 such asLEDs light up to indicate that the power is on and indicate which presetlaser program/power level the device is set to perform at.

Upon initial power up in step 101, the lowest power level isautomatically set by for the user by the system control program of thecontroller of the control board 9. In step 102, the user may now pressthe power button 4 such as a power/program select button 4 to change thepower/program that will be used once the laser is in operation. The usermay continue to press the power button 4 to cycle through power levelssuch as low to medium to high, back to low, and so forth. Each time thepower button 4 is pressed, the LED lights of the indicator lighting 3change configurations to represent the power level selection. Low poweris represented by the second LED from the bottom of the laser device 23,medium power is represented by the third LED from the bottom of thelaser device 23, and high power is represented by the top LED of thelaser device 23. The bottom LED of the laser device 23 is used torepresent that the power is on.

There can be more than 3 power levels used within the laser system 10.In one example, 5 power levels are used. This enables the user to selectthe best level to meet their needs during use and ideally avoid anyphysical discomfort to the user. The system 10 may be reprogrammed for 4power levels by using all four LEDs 3 as power levels 1 through 4 andomit a power-on light which can be assumed by seeing one of the powerlevel lights on or hearing the start-up jingle. An alternative handheldlaser design uses a digital LCD (or LED) screen to show the powerlevel/program for the system 10 using symbols, numbers, or letters.

Once the user completes step 102, the user then completes step 103 byholding the laser as shown in FIG. 3. Then, the user completes step 104by pressing the laser aperture 1 against their skin where the userdesires laser treatment such as on the face to address facial wrinklesor acne. Once the laser aperture 1 is fully touching the skin, the usercompletes step 105 and presses the initiation button 2 to begintreatment on the spot where the laser is currently positioned.

At this point, the controller of the system control board 9 begins theselected program of step 102. Step 106 is initiated by the program todetermine if all safety sensors 8 are engaged with the skin. If any ofthe safety sensors 8 are not engaged with the skin, the system 10controls will not energize the laser and instead will provide a low-toneaudio sound representing that the system 10 is not firing due to lack offull engagement of all safety sensors 8 with the skin. After soundingthe low-tone audio sound, the program will move back to step 104, whichallows the user to reposition the laser system 10 and move onto step105.

At step 106, if the safety sensor 8 is fully engaged on the skin, thecontroller of the control board 9 will begin firing the light emittingdevice 7 in step 107 according to the pre-programmed power levelselected in step 102. During the firing of the light emitting device instep 107, the controller of the control board 9 will continually pollthe safety sensor 8 in step 108 to ensure it is fully engaged againstthe skin. If step 108 shows the safety sensor 8 continues to be fullyengaged, it will then determine if the program is done step 109 based onthe pre-programmed timers and pulsing program. If the program is notdone in step 109, it will cycle back to step 107 and continues thetreatment program. If the safety sensor 8 in step 108 is ever determinedto be not fully engaged with the skin, then the system 10 controls willimmediately stop providing energy to the light emitting device 7 andwill move to step 110.

If step 109 determines the program is complete, then the controller ofthe control board 9 will immediately stop providing energy to the lightemitting device 7 and move to step 110. At step 110, the system 10control will make an audio sound through the speaker or buzzer on thecontrol board 9 to signal to the user that the treatment sequence iscomplete. In step 111, the system controller then wait for the safetysensor 8 to be disengaged from the skin. This step requires the user todisengage the system's safety sensors 8 from the skin before the programwill end in step 112. The sequence of step 111 and step 112 requires theuser to remove the device 23 from the skin before the program will endand allow the user to resume use of the system 10. This provides safetyto the user so that the user does not treat the same skin repeatedly,such as by mistake, by simply pressing the initiation button 2 multipletimes without first moving the system 10 off the skin.

Step 112 ends the treatment program while keeping the power on andmaintaining the current program setting. At this time, the user willmove the laser into the next position in step 104 and continue treatingtheir skin until all desired skin is treated at the selected powerlevel. If the user feels the onset of pain in certain areas of theirskin, such as directly under the eyes where skin is most sensitive, theycan move back to step 102 to select the correct power level for the skinbeing treated and then proceed through the process flow accordingly. Ifthe user feels the that power is not sufficiently high in certain areasof their skin, such as on the forehead where skin is less sensitive,they can move back to step 102 to select the correct power level for theskin being treated and then proceed through the process flowaccordingly.

During step 105, the system controller will make an audio sound toinform the user that the treatment has started successfully. The audiostart-treatment sound of steps 105 and the audio stop-treatment sound ofstep 110 provides the user with a clear indication of when the laserstarts and when it stops during full programmed operations with thesafety sensors engaged correctly. The user can use these audio promptsto better acclimate themselves with the system, which facilitates movingthe system 10 from spot to spot around the skin of their face in asystematic and paced manner, in one example.

An alternative programming of the system controller omits step 105 andallows the system to initiate step 107 as soon as step 106 is fulfilled.This method increases the speed of overall treatment because the user nolonger needs to trigger the initiation button 2 with each treatmentcycle. While this approach is considered more efficient, the priormethod is considered safer as it requires direct user initiation eachtime the system is triggered.

Once the user is completely done treating the skin, they can allow thesystem to shut down automatically, as the system is programmed totime-out within a short time of no buttons being pressed (which istypically about 2 minutes). Alternatively, the user holds power button 4for more than about 1 second and the system 10 will fully power down,When the system 10 powers down, it plays a lower-tone jingle as comparedto the start-up tone, and all the LEDs 3 turn off.

To charge the battery on the device 23, the user plugs a wall charger,computer charger, or car charger to a power source. Then, the user plugsthe system power end into the handheld system 10. LEDs 3 on the system10 will flash until the battery is fully charged, then an audio soundwill play and the LEDs 3 will turn off when the system 10 is fullycharged. An alternative power-down sequence omits the audio portion soas not to disturb the user. The power cord to charge the system 10 maybe configured to have a micro-USB end and a computer USB other end forpowering by computer USB interface.

In additional examples, the system 10 can includes an additional jack orinterface that accepts a computer USB plug input, and can includeswall-plug electrical outputs for plugging into a wall-plug outlet forcharging. When the system 10 is charging, LED lights preferably indicatethe level of battery charging completed or the amount of time left tocomplete charging.

Each time the system 10 is powered up by pressing button 4, the LEDs 3typically briefly display a number of lights that indicate the amount ofcharge left in the battery.

The port 5 of FIGS. 1 and 2 is used to charge the system battery andconnect the system 10 to another device. By connecting the system 10 toanother device such as a personal computer, the system 10 can updatesits firmware program, download usage data, or customize userpreferences. In one example, the port 5 is a USB connection or similarinterface which can auto-negotiate a connection with outside device(s).

Using this connection, the controller of the control board 9 in thesystem 10 can automatically execute programs to update its systemprogram or upload data and/or initiate a program that allows users tointerface with the system's program via an external device such as apersonal computer. Through this connection to a defined program, thesystem 10 can upload usage data which such program or external websitecan analyze, graph and/or provide other feedback to the user. Suchfeedback can advise the user on how to improve useage of the device.Through this connection, a defined program can allow the user tocustomize the program settings or power levels to better match theuser's needs, Through this connection, a defined program could allowusers to modify the audio and LED prompts to more desirable or preferredsettings.

An alternate battery charging method may be used whereby electricalconnections from the system 10 connect with a base-station when thesystem 10 is not in use. The base-station is connected to electricalpower and may automatically charge the system 10 once the system isplaced into the base station. The base-station may charge the system 10through inductive charging or via direct electrical connection chargingcurrent.

The flow chart illustration of FIG. 6 shows an open-loop control oftemperature based on pre-programmed settings and user definitions of thepower/program setting according to their comfort level. Using thisopen-loop control, there is no direct temperature measurement of theepidermis 27 or dermis 28 during operation of the system 10. Analternate method of treatment is to add a temperature measurement deviceto measure temperature at or near the treatment area that can correlateto the epidermis 27 or dermal temperature of interest during thetreatment of the skin and adjust one or more of the program attributes(laser power, pulse width, time delay between pulses, or total number ofpulses) to maintain a desired temperature.

In accordance with aspects of the present invention, there is providedan improved method employing a laser apparatus. This laser apparatusemits pulse groups having pulses that deposit energy into the tissue inprecisely metered formats that raise the local temperature at atreatment site in the skin to a desired level. Then, this laserapparatus maintain that desired temperature level for a selected period.

This method provides localized heating of target spots on the skin of apatient by the application of optical laser energy to the spot. Thecontroller of the control board 9 provides for the delivery of opticallaser energy to the target spot of skin in the form of a group ofpulses, using a combination of pulsed beam parameters selected fromlaser power, pulse width, time delay between pulses, and total number ofpulses. Delivery of this energy to a target spot in the affected skincauses initial heating so that the temperature of the target spot risesquickly to a desired first temperature range. Next, the temperature inthe skin is maintained within a selected temperature maintenancetemperature range by controlling, in the pulses, at least one of thesesystem attributes laser power (also referred to as pulse intensity),pulse width, time delay between pulses, and total number of pulses.

The maintained temperature of the method is preferably greater thanabout 39 degrees Celsius. Preferably, the maintained temperature isgreater than about 39 degrees Celsius and less than about 45 degreesCelsius. Experimentation has shown that less one or two degrees C. below39 degrees C. provide less than optimal results, and two or more degreesbeyond 45 degrees C. increases pain in the patient without improving theefficacy of the treatment.

A method is provided for treating skin of a human patient using a laserapparatus capable of producing an emission of laser energy in the formof a group of pulses having defined parameters. Using an opticaldelivery system for transmitting the defined pulse group of pulses oflaser light energy, as shown in FIGS. 7-15, to the same spot on the skinof the patient. This enables the temperature or energy level to risequickly to a desired level in the specified layer of the skin based onthe laser wavelength absorption physics. Once the desired temperature isanticipated to be reached, the pulse parameters are pre-programmed tochange to maintain this desired temperature or energy level for a periodof time.

More specifically, as shown in FIGS. 8 and 9, the pulsed group powergenerated under the control of the controller of the control board 9 isnot constant and typically starts out at a high power level and longpulse duration until the desired temperature is reached. At this point,one or more of the pulse attributes or parameters (pulse power/lasercurrent, pulse width, and time delay between pulses) is changed by thecontroller of the control board 9 to lower the amount of power appliedinto the skin from that point forward so as to maintain the temperatureat a relatively constant level. In FIGS. 8 and 9, the laser power levelis decreased once the desired temperature is reached or anticipated tobe reached by the controller of the control board 9. The transition frominitially driving high levels of energy (optical fluence) into the skinto maintaining the skin temperature can occur in many steps orconfigurations, utilizing different combinations of pulseattributes/parameters to attain the identical and desired outcome. InFIGS. 8 and 9, the laser power level is decreased by the controller ofthe control board 9 in two steps using a total of 3 power levels toachieve the desired temperature profile. Alternate methods may reducethe power in 4 or more steps, or as few as two steps, in examples.

FIGS. 8-15 show examples of modifying one or more system parameters in anon-linear way to achieve an expected desired temperature profile thatraises temperature quickly in the desired tissue, then maintains theexpected desired temperature once it is reached. In general, the overallenergy provided to the skin is typically between 1.5 and 5.0 joules percentimeter squared.

The examples shown in FIGS. 8 & 9 changes the laser energy output byvarying the power level per pulse and the number of pulses at each powerlevel. This is accomplished by having a steady stream of pulses of highpower, which can be followed by pulses of medium power, and then pulsesof lower power. All. of these pulses have the same time delay betweenthem and the same pulse width. In this example, the high power pulsesdrive the skin temperature quickly to the expected desired level thenthe medium power tapers off the increase of the temperature rise suchthat it does not overshoot the desired level. The lower power levelprovides enough energy to maintain the desired temperature in the skin.These patterns are typically predetermined for particular skinconditions, skin types, and lasers, and stored in a control device suchas a computer.

An alternate way to control the laser energy output is to vary the timedelay between pulses. This is accomplished by having a steady stream ofpulses with small time delays between pulses followed by pulses ofmedium time delay between pulses and 3 pulses of longer delays betweenpulses. All the pulses having the same power level and the same pulsewidth as shown in FIG. 10. In this example, the pulses with small timedelays between pulses drive the skin temperature quickly to the desiredlevel then the pulses with medium time delays between pulses taper offthe increase of the temperature rise such that it does not overshoot thedesired level. The pulses with long time delays between pulses provideenough energy to maintain the desired temperature in the skin.

Another way to control the laser energy output is for the controller ofthe control board 9 to vary the pulse width of subsequent pulses, suchas having long pulses followed by pulses of medium pulse width andpulses of shorter pulse width. All the pulses have the same power leveland the same time delay between pulses as shown in FIG. 11. In thisexample, the pulses with long pulse widths drive the skin temperaturequickly to the expected desired level then the pulses with medium pulsewidths taper off the increase of the temperature rise such that it doesnot overshoot the desired level. The short pulse width pulses provideenough energy to maintain the desired temperature in the skin.

Another way to control the laser energy output is to vary multiple pulsesettings at the same time. For example, the pulse width and time delaybetween pulses is varied as shown in FIG. 12. Alternatively, the pulsewidth, the time delay between pulses, and the power level of the pulsesare all varied as shown in FIG. 13.

Another way to control the laser energy output is to provide highinitial energy pulses to raise the temperature as quickly as possible,and then follow with a lower power level of pulses to allow the initialenergy of the high level pulses to dissipate into the skin and achieve auniform expected desired temperature level of this skin. This is thenfollowed by medium-level power pulses to maintain the desiredtemperature level within the skin.

For example, FIG. 14 shows high intensity pulses followed by lower-levelintensity pulses followed by medium level intensity pulses which drivethe skin temperature to an expected given level and maintain that levelin a relatively flat and constant level for a period of time. Thismethod of the controller of the control board 9 can also be performedusing similar pulse widths and time intervals between pulses. Instead ofusing laser power intensity, the same transition of energy from high tolower (to allow dissipation) to medium (for temperature maintenance) canbe achieved by varying pulse width (long to short to medium), or timedelay between pulses (short to long to medium), or a combination of anyor all of these.

Another way to transition the laser energy output is to vaty the powersetting (laser output intensity in Watts) in constant-wave form (i.e.,the laser diode is always on during the treatment cycle). For example,the laser intensity can start out high, then decrease as the expecteddesired skin temperature is being reached as shown in FIG. 15.

In any of the preceding examples (FIG. 8-14), the number of pulseswithin each laser pulse grouping can be varied and the number ofgroupings may be varied of the controller of the control board 9 tofurther refine the control of the energy into the skin and desiredtemperature outcome within the skin. For example, instead of 3transition steps there may be 2, 4, 5, or more than 6, in examples.

In any of the above approaches, a temperature measurement feedbackdevice can be deployed in the system to measure temperature during thetreatment cycle. This temperature measurement is used to change one ormore of the laser parameters (including laser power or intensity, pulsewidth, and time delay between pulses) to reach the desired temperaturelevel and maintain this temperature level relatively constant for aperiod of time. This is often referred to as “closed-loop” controllingof the system. The prior descriptions of the system without a directtemperature measurement are often considered “open-loop” systems as theyhave no direct feedback on the actual outcome during treatment.

Tables 1 2, 3, and 4 herein below, and FIGS. 16, 17, 18, and 19 describeoperative examples of the system 10 that are controlled by thecontroller of the control board 9.

In one example, a single laser system 10 was programmed with 3 powerlevels to represent low, medium, and high treatment energies. As shownin Table 1 and FIG. 16, the low setting has the fewest pulses of highpower pulses of 5.5 Amps (2.55 Watts of optical laser power) As shown inTable 2 and FIG. 17, the medium setting has more pulses in the highsetting and is otherwise identical to the low setting. Thus, the mediumsetting reaches a slightly higher temperature level before leveling off.Table 3 and FIG. 18 describe the high setting which is similar to themedium setting except that it has many more pulses in Group 3 tomaintain the temperature for a longer period of time and thereby allowmore energy into the skin without necessarily raising the temperaturelevel within the skin, which might cause pain and discomfort for thepatient.

Table 4 and FIG. 19 represent the method of high power pulses followedby low power pulses followed by medium power pulses. This method allowsfor a high power level causing a fast temperature rise to the targetedtemperature followed by the lower power level which allows for thetemperature to diffuse without crossing the pain threshold followed bythe medium power level which allows for the temperature to be maintainedat a desired level. This example characterized by table 4 and FIG. 19represents a method for a high power setting which emits 3.0 joules persquare centimeter and could be complimented by similar pulse train whichemits approximately 2.8 joules per square centimeters for medium andanother pulse train which emits about 2.5 joules per square centimeterfor the low power setting.

Table 1 directs 3.1 Joules into a 4 millimeter (mm)×4 millimeter (mm)spot size with the following parameters:

Group 1 Group 2 Group 3 Laser Current 5.5 4.5 3.0 Amps Laser Power 2.552.11 1.37 Watts Pulse Width 5 5 5 milliseconds Duty Cycle 70 70 70 %Pulses 5 15 40 Joules 0.06 0.16 0.27 J/cm2 0.40 0.99 1.71 Total Joules0.50 Total J/cm2 3.10

Table 2 directs 3.5 Joules into a 4 mm×4 mm spot size with the followingparameters:

Group 1 Group 2 Group 3 Laser Current 5.5 4.5 3.0 Amps Laser Power 2.552.11 1.37 Watts Pulse Width 5 5 5 milliseconds Duty Cycle 70 70 70 %Pulses 10 15 40 Joules 0.13 0.16 0.27 J/cm2 0.80 0.99 1.71 Total Joules0.56 Total J/cm2 3.50

Table 3 directs 3.73 Joules into a 4 mm×4 mm spot size with thefollowing parameters:

Group 1 Group 2 Group 3 Laser Current 5.5 4.5 3.0 Amps Laser Power 2.552.11 1.37 Watts Pulse Width 5 5 5 milliseconds Duty Cycle 70 70 70 %Pulses 10 12 50 Joules 0.13 0.13 0.34 J/cm2 0.80 0.79 2.14 Total Joules0.60 Total J/cm2 3.73

Table 4 directs 3.00 Joules into a 4 mm×4 mm spot size using a stepmethod of high power pulses followed by low power pulses followed bymedium power pulses.

Group 1 Group 2 Group 3 Laser Current 5500 1000 2000 Amps Laser Power1.6 0.141 0.457 Watts Pulse Width 5 5 5 mseconds Duty Cycle 70 70 70 %Pulses 35 30 74 Joules 0.29 0.02 0.17 J/cm2 1.81 0.13 1.06 Total Joules0.48 Total J/cm2 3.00

While this invention has been particularly shown and described withreferences to preferred embodiments thereof it will be understood bythose skilled in the art that vatious changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

What is claimed is:
 1. A method for treating a patient by providinglocalized heating of target spots of skin, comprising: applying opticalenergy having a wavelength between 1380 nanometers (nm) and 1570 nm tothe target spots of skin using a laser source system such that the skinis heated so that a temperature of each target spot rises to a desiredtemperature range of greater than 39 degrees Celsius and less than 45degrees Celsius; and maintaining the temperature in the target spotswith the system within the desired heating temperature range bycontrolling, in pulses, at least one pulsed beam parameter being pulseenergy intensity, pulse width, or a time delay between pulses, whereinone or more of the pulsed beam parameters change during the applicationof the optical energy, wherein the optical energy is applied and theenergy penetrates to a depth between 100 microns and 800 microns.
 2. Themethod of claim 1, wherein the one or more pulsed beam parameters areinitially set to raise the temperature in the skin, then as the heatingprogresses the beam parameters are changed so as to maintain the desiredtemperature range in the skin.
 3. The method of claim 2, wherein thepulses are applied in a first group of pulses to quickly heat the skinto a target temperature, and thereafter the pulses are applied in asecond group of pulses to decrease a rate of temperature increase in thetarget, followed by a third group of pulses to maintain the temperatureof the target for a defined period.
 4. The method of claim 3, whereinthe second group of pulses provides less energy/time than the firstgroup of pulses and the second group of pulses provides greaterenergy/time than the third group of pulses.
 5. The method of claim 2,wherein an interval between pulses increases over time to maintain atissue temperature in the desired heating temperature range duringtreatment.
 6. The method of claim 2, wherein the pulses are of variablewidth and the width of the pulses decreases over time to maintain atissue temperature in the desired heating temperature range duringtreatment.
 7. The method of claim 2, wherein the energy intensity variesover time to maintain a tissue temperature in the desired heatingtemperature range during treatment.
 8. The method of claim 1, whereinthe energy conveyed maintains a dermal temperature of the target spotsbetween 39 degrees Celsius and 45 degrees Celsius for greater than 0.5seconds.
 9. The method of claim 1, wherein a safety sensor near anaperture detects a contact or near-contact with the skin, and the methodincludes only emitting energy while the safety sensor continues todetect contact or near-contact with the skin.
 10. The method of claim 1,wherein the laser system that performs the method is connected by a wireor through wireless communications to another device to complete one ormore operations, the operations including updating device software,downloading device data, and charging device battery.
 11. The method ofclaim 10, wherein once the laser device is connected to another device,the laser system automatically launches a program to begin datacommunications between the laser system and device.
 12. The method ofclaim 1, wherein one or more pulsed beam parameters are initially set tonot raise the temperature in the skin above 25 C, then one or morepulsed beam parameters are changed to raise the temperature in the skin,then as the heating progresses the beam parameters are changed so as tomaintain the desired temperature range in the skin.
 13. A laser systemheating of target spots of skin for treating a patient, comprising: alaserengine of the laser system for generating light having a wavelengthbetween 1380 nm and 1570 nm that is applied to the target spots of skin;and a controller configured to drive the laser engine to generate lightto maintain a temperature in the target spots within a desired heatingtemperature range of greater than 39 degrees Celsius and less than 45degrees Celsius by controlling, in pulses, at least one pulsed beamparameter of the laser engine being a pulse energy intensity, pulsewidth, or a time delay between pulses, the controller being furtherconfigured to change one or more of the beam pulsed parameters duringthe application of the optical energy, wherein the optical energy isapplied during a treatment time, and the controller being furtherconfigured to drive the laser engine at a high fluence into the skinfollowed by a lower fluence within the treatment time, and wherein theenergy penetrates to a depth between 100 microns and 800 microns. 14.The system of claim 13, wherein the one or more pulsed beam parametersare initially set to raise the temperature in the skin, then as theheating progresses the beam parameters are changed so as to maintain thedesired temperature range in the skin.
 15. A method for treating apatient by providing localized heating of target spots of skin,comprising: applying optical energy having a wavelength between 1380 nmand 1570 nm to the target spots of skin using a laser source system suchthat the skin is heated so that a temperature of each target spot risesto a desired temperature range of greater than 39 degrees Celsius andless than 45 degrees Celsius; and maintaining the temperature in thetarget spots with the handheld system within the desired heatingtemperature range by controlling, in pulses, at least one pulsed beamparameter being a pulse energy intensity, pulse width, or a time delaybetween pulses, wherein one or more of the pulsed beam parameters changeduring the application of the optical energy, wherein the energypenetrates to a depth between 100 microns and 800 microns, wherein theone or more pulsed beam parameters are initially set to raise thetemperature in the skin, then as the heating progresses the pulsed beamparameters are changed so as to maintain the desired temperature rangein the skin with the pulses being applied in a first group of pulses toquickly heat the skin to a target temperature, and thereafter the pulsesbeing applied in a second group of pulses to decrease a rate oftemperature increase in the target, followed by a third group of pulsesmaintaining the temperature of the target for a remainder of thetreatment time, wherein a safety sensor near an aperture detects acontact or near-contact with the skin, and wherein the system emitsenergy only while the safety sensor continues to detect contact ornear-contact with the skin.
 16. A method for treating a patient byproviding localized heating of target spots of skin, comprising:applying radio-frequency (RF) energy to the target spots of skin using asystem such that the skin is heated on that a temperature of each targetspot rises to a desired temperature range of greater than 39 degreesCelsius and less than 45 degrees Celsius; and maintaining thetemperature in the target spots with the system within the desiredheating temperature range by controlling, in pulses, at least one pulsedparameter being pulse energy intensity, pulse width, a time delaybetween pulses, or pulse frequency wherein one or more of the pulsedbeam parame e s change during the application of the RF energy, whereinthe RF energy is applied and the energy penetrates to a depth between100 microns and 800 microns.